中国国家发展和改革委员会于2021年出台了一份重要的政策文件（《关于进一步完善分时电价机制的通知》），要求各省对几乎所有的用户都要设计和实施分时电价。这将极大地推进分时电价在中国的实施，并使中国成为少数几个尝试在全国范围内广泛实施分时电价的国家之一。
通过实行分时电价形成的电力消费模式的改变也可为系统提供多种好处。然而，要实现这些好处，分时电价的费率标准必须要设计得当，确定分时电价的费率要准确反映系统内在的成本，而不是靠更简单的“经验法则”。按照发改委2021年文件的要求，各省已出台了分时电价实施的配套政策，并由此产生了是否、何时以及如何评估和优化这些配套政策的一系列问题。
本政策研究简要回顾了分时电价费率设计的原则及美国一些地区的相关经验，并重点讨论如何设计分时电价的费率结构，从而实现最大化的经济和环境效益。
本文首刊于《南方能源观察》（2023年4月26日）
City dwellers without their own parking space, small business owners such as taxi drivers and a growing number of car-sharing users rely on the public charging network to access electric driving. The affordability of electric vehicles (EVs), compared to the fossil-fuelled cars they replace, in part, relies on not only upfront cost but also lower running costs.
The recent fossil gas crisis has led to high energy prices that make fixed-price electricity contracts expensive and affect those running costs. This should get those who procure, operate and use public charging infrastructure thinking: Which charging models help reduce fossil fuel dependence in transport and energy, and make public charging more affordable?
Currently, most public charging prices are flat rates. Users pay the same price whether they charge during the evening peak or overnight. Tariffs are high to cover peak prices within the energy supply contract. Yet they do not help reduce peak electricity demand, nor are the lower costs of charging off-peak passed on to EV drivers.
Smart charging is a solution that reduces costs for EV drivers, provides assurance for future EV users and supports the electricity system in the transition to renewable energy sources. It also, importantly, maintains or even improves the profitability of charge point operators. We need to extend the benefits of smart charging to users of public charging networks, as high prices turn otherwise interested drivers away from EVs.
Electricity prices on wholesale markets fluctuate: there are clear differences between days and within each day. In 2022, these differences increased six-fold compared to 2020, meaning that there is even more money to be saved if drivers can take advantage of price fluctuations.
EV charging flexibility can enable a reduction in energy demand at peak times. This not only lowers the price for individual drivers, but it also decreases costs for all power system users as it reduces the need for peak power plants that run on expensive fossil fuels.
EV drivers with their own home charging port can keep their bills under control by shifting sessions to cheaper periods, for example, through a time-varying or dynamic pricing contract with their supplier.
A dynamic tariff reflects wholesale prices in retail tariffs, for example with hourly prices communicated a day in advance. Homeowners can also save by investing in rooftop solar for their charging needs.
What can be done to offer EV drivers who rely on public charging points equal opportunities?
The UK government and energy regulator Ofgem recognise the importance of extending the benefits of smart charging for users and the energy system and included public charging in their joint 2023 Smart Charging Action Plan.
This requires changes to the status quo, however, in the UK and across Europe. Currently, customers and the electromobility service providers offering charging subscriptions have little choice but to accept the energy prices set by the charge point operator (CPO). Unfortunately, charging subscription prices usually reflect the most expensive CPO rates—so even if cities keep prices stable in their concession to operate the charging infrastructure, EV drivers often still pay more because of rising prices in other places.
CPOs and electromobility service providers could help EV drivers lower their bills by enabling user-centric smart charging services. As the name indicates, these services place consumer needs first, including enabling access to the lowest possible rate within the driver’s desired charging period.
Automation can help with the lower charging speeds typical for on-street charging when parked. For fast charging, an activity where people typically stay nearby their vehicle while the charging is happening, time-varying pricing—as offered by a growing number of operators—could affect when drivers show up at the station.
EV drivers can see the prices a day in advance, allowing them to plan and benefit from lower off-peak charging rates.
Cities can also look for ways to maximise local benefits. One way to do so is by connecting EV charging to locally produced clean energy from citizen-owned renewable energy communities.
The same smart charging technology that is based on dynamic prices from wholesale markets can also match EV charging sessions with wind and solar energy. In some countries, renewable energy communities even benefit from reduced network tariffs as they help use local networks more efficiently.
Provided discounts are genuinely reflective of the value added, this allows the expansion of renewable energy generation and the charging network to go hand-in-hand while ensuring predictable and affordable prices. Combined with car-sharing, EV charging within a renewable energy community offers the benefits of both generating renewable electricity and promoting the use of electric cars to city dwellers.
This solution can further reduce private car ownership by making sharing an attractive option.
A wide range of available smart charging services have demonstrated that the perceived complexity of dynamic prices can be handled in a user-friendly way, such as with retail rates that offer off-peak extra points. Consumers will benefit from a broad diversity of offerings, as not all will have the same preferences and needs. They might want to try out different options to find their perfect match. It is important that consumers feel confident in offering and benefiting from the flexibility that EV charging can provide.
Facilitating dynamic pricing is an important step forward that can benefit the entire energy ecosystem, minimising the costs of the transition. Everyone benefits from energy system cost savings achieved through EV charging responding to dynamic price signals. The local planning process offers the perfect opportunity for authorities and grid operators to reflect the value of smart charging in their vision for a decarbonised energy system.
Governments and regulators can give EV drivers with and without off-street parking the same opportunities to participate in and benefit directly from smart charging. It is a sustainable way to bring smart charging rewards to all EV users.
A version of this article originally appeared on Foresight Climate & Energy.
The cost of heating leaves many European households feeling burnt. Three-quarters of our heat is still supplied by expensive fossil fuels, and heating homes is Europe’s biggest gas user, which creates a twin dilemma: How do we clean up heat, while lowering costs for those who can least afford it?
There is good reason for the growing attention paid to heat decarbonisation. Heating and cooling buildings accounts for one-quarter of energy use in Europe. Meeting the European Union’s climate target by 2030 means that an equivalent of 1 in every 4 homes will need to replace their heating systems with a clean alternative between 2026 and 2030. Some countries are already taking the bull by the horns, with at least nine EU member states announcing policies to phase out fossil heating.
What will they replace it with? The lower-cost direction of travel is now clearer than ever: efficient heat pumps, district heating and home energy efficiency. These technologies are widely expected to be the most affordable clean heat solutions over the coming decades. Burning coal, oil and hydrogen for heating are predicted to be the most expensive.
These clean heat options, however, have not been the most affordable prior to the energy crisis, largely due to both higher upfront investment costs and the big gap between cheaper fossil fuel and more expensive electricity prices. Not even the high efficiency of a heat pump was able to overcome this difference in running costs.
For low-income households, the promise of affordable, clean heat has been still further away. Even before the current price crisis, to save on energy costs, low-income households were using less energy for heating than they needed to keep them warm. An additional lift is required, therefore, to both switch to clean heat and ensure that their heating is affordable enough to overcome the need for rationing.
Even if the economics of clean heat have improved, the affordability has worsened.
The cost impact of switching from underheating to full heating is significant. In the countries we looked at in our recent study, Taking the burn out of heating for low-income households, a heat pump providing full heating over the course of its 18-year lifespan could be up to twice as expensive as the prevailing fossil fuel system, which provides 20% less heat.
The shocks of the energy price crisis of 2022 have closed the cost gap between standalone heating technologies. Suddenly, heating with a heat pump has become more affordable than heating with fossil fuels in many EU countries, both in terms of running cost and the total cost of ownership. Based on these improving economics, many households who could switch to a heat pump now would. Not only would it be a cleaner heating solution, but it would also lower their energy bills.
There is one major caveat, however. Even if the economics of clean heat have improved, the affordability has worsened. From a total cost of ownership perspective, a heat pump may have been cheaper than a gas boiler in 2022, but it was still much more expensive than a heat pump or a fossil boiler in 2021.
Making clean heat systems not only economically competitive but affordable over the long term requires a wide array of solutions. First, we can start by reducing the upfront cost. In the EU, 25 of 27 countries subsidise clean heating systems. (Whether these schemes are sufficient in budget terms, or are ‘fig leaf’ schemes, is another story). Only nine of these schemes, however, offer higher funding levels for households on lower incomes or funding generous enough for people without significant savings to invest. Even amongst these schemes, design flaws limit access to most of them. Only one framework, the French system, has a dedicated, long-term budget for clean heat for low-income households.
Making clean heat systems not only economically competitive but affordable over the long term requires a wide array of solutions.
But providing the heating system at low cost is only part of the story. It’s vital to reduce the running costs to make heat more affordable for the lowest-income households. This means investing heavily in energy efficiency measures to reduce the overall need for heating and a range of measures to make electricity cheaper. Providing heating services to which customers can subscribe, like heat-as-a-service, could also help to: combine upfront and running costs, offset these costs with grants and bill subsidies, and offer predictable, stable heating bills to improve affordability and security for low-income customers.
Solutions also depend on the heating context. In contrast to installing a heat pump, households connecting to a district heating system tend to face lower upfront connection costs that may even be bundled with the ongoing cost of the heat supply. Yet, they face other challenges, and the focus on affordability for district heating is less on upfront expenses and fuel costs and more on subscription pricing, service charges and consumer protection.
The risk of remaining reliant on fossil fuels for low-income households is clearer now than ever. Those whose budgets are already stretched to and beyond the breaking point are least able to absorb unpredictable price swings, yet they are those most drastically exposed to them. To guarantee affordability for low-income households during a clean heat transition, it is critical that they come first, not last. That means designing support policies with their needs in mind and ‘going big’ on energy efficiency as these homes switch to clean heat. Energy efficiency also opens the door to cheaper electricity when we use it at different times of the day.
Let’s decarbonise European homes without setting household budgets on fire.
Improving affordability also means shifting energy costs away from electricity, so that policy costs, such as taxes and levies, do not slow down the transition. Lastly, it means “innovating inclusively,” so that the snazzy new energy stuff focuses on the needs of low-income households. Designing gadgets and policies for those with the least time and the greatest barriers to engage has the added benefit of extra convenience for others.
Let’s decarbonise European homes without setting household budgets on fire. Only by prioritising the needs and wallets of the most vulnerable can we affordably and equitably clean up how we heat our homes.
The original version of this article first appeared in Energy Monitor.
Featured image by Mihály Köles via Unsplash.
The rapid and parallel growth in both variable electricity production from wind and solar, and in large inherently flexible loads (such as electric vehicles and heat pumps) presents an opportunity to ensure that each transition is both reliable and affordable. In a future that will be increasingly capital-intensive, demand flexibility can significantly reduce the amount of infrastructure that must be financed. But much remains to be done to access that potential, most of which is beyond the reach of traditional approaches to demand response.
The primary focus must shift from strategies that require flexible demand to mimic centrally dispatched generation, to strategies that empower consumers to save money by linking their consumption more dynamically to daily fluctuations in variable supply. At a retail level, this includes adopting a series of innovations that widen consumers’ access to the untapped potential for flexible loads to reduce costs and lower electricity bills. At the wholesale level, it means attacking institutional practices that discriminate against flexible demand reliant on energy market pricing, and that artificially depress energy prices by pre-emptively committing consumers to pay for uneconomic investments through forward capacity mechanisms. Overall, it means progressively assessing and integrating responsive demand into forward resource planning and procurement processes.
This paper is one of a series of eight produced by ESIG’s Aligning Retail Pricing with Grid Needs Task Force, led by RAP’s Carl Linvill. The task force examined ways that retail pricing may be used more widely and more efficiently to allow flexible demand to respond to grid needs.
中国的可再生能源增长势头不减，为达成双碳目标打下了良好的基础。随着可再生能源在能源结构中占比越来越高，如何在保障供电稳定性和系统安全的前提下，调整当前电力系统，深化市场改革，实现可再生能源带来的环境及经济效益的最大化，成为了一个亟待解决的挑战。目前包括中国在内许多国家都在尝试解决这一问题，并在很多方面取得了一定进展。其中，分时电价在全中国范围内的推行是一个很重要的里程碑。本文总结分析了中国在此方面做出的努力及成果，并结合国际经验，为地方政府更好地落实国家政策提供了一些思路。
近年来，为了改善电力供需情况，促进可再生能源消纳，国家发改委及能源局出台了许多措施，而分时电价就是其中的几个主要措施之一。分时电价是指将一天分为多个时段，并且针对各时段制定不同的电价。具体来说，是将电价在电力系统紧张，亦即用电需求高、发电资源边际成本高昂时定价在高位；而在系统形势较宽松时定价在低位。通过价格信号引导用户调整用电时间，以达到削峰填谷的作用。有些地区也会考虑冬夏、枯丰水期对系统成本的影响，制定季节性的分时电价。分时电价还有许多立竿见影的环境和经济上的收益，例如带动负荷向低成本、低排放时段转移，以及减少调峰资源（如火电）的需要。在近期的文章中我们就此分享了更多细节。
国家发改委在2021年颁布的《关于进一步完善分时电价机制的通知》提出了一些指导性的意见，旨在拓宽、深化分时电价政策，进一步塑造以新能源为主体的新型电力系统。根据国家指导，各地区也相应出台了省级分时电价政策。这些政策响应了《通知》的号召，许多地区制定了尖峰电价机制、也将峰谷电价差在合理范围内拉大。
值得注意的是，《通知》中还开创性地提出要“建立分时电价动态调整机制”，并且各地区的分时电价政策也对此有所响应。然而，多数省份暂时尚未提出具体、详尽的实施办法。就此，本文将借鉴国际经验并结合中国国情，简短讨论分时电价动态调整机制的重要性，以及以下三点设计思路：常规评估、有据调整、公开方法。
中国各地方在2021及2022年陆续出台了完善分时电价政策的相关文件，然而若想最大程度地发挥分时电价的优势，对分时电价的动态调整也必不可少。例如，在太阳能发电资源快速增长的美国加州，政策制定者近年出台了系统化的动态调整机制来调整分时电价峰段划分，用以解决困扰加州已久的居民电价与电力供需情况不符的状态。以加州南部的圣地亚哥区域为例：这一区域内的分时电价设计在十数年间，都沿袭了大规模开发太阳能资源前的电价——电价高峰时段被定为上午11点至下午6点之间，以降低日间用电量。可随着近年来太阳能发电量比重逐渐增加，低成本且环保的电力资源在日间激增。然而傍晚日落时，太阳能出力逐渐减少，又恰逢居民用电高峰，导致傍晚时段电力系统供电紧张。分时电价调整的滞后导致了电价设计与系统成本的脱节。自2017年开始，为了让分时电价“重回正轨”，分时电价的高峰时段被改至傍晚4点到9点。这样一来，日间的太阳能资源能够得到更好的利用，并且傍晚时段的用电高峰也得以控制。政策制定者通过分析系统情况，给正在发生深刻变化的电力系统“把脉”，并及时调整分时电价以应对这些变化。动态调整分时电价不仅放大了可再生能源的经济效益，也缓解了可再生能源并网波动所带来的系统压力。
在日新月异的中国电力系统内 ，实施常规评估有益于保证分时电价与系统总成本变化方向相符。理论上来说，随着可再生能源渗透率与电气化程度越来越高，电力系统的供需条件也会随之改变，并且系统电力成本也会发生变化。此外，由于分时电价的确立是建立在对未来几年的预估之上的，对于中国目前正在经历变革的电力系统而言，这些预估的假设基础很可能在未来几年发生较大的变化，使系统电力成本改变、偏离预估值。确保分时电价可以及时跟进电力成本变化的基础是常规评估——此类评估大多通过对边际成本的分析，来确保分时电价的高峰时段可以贴合电力系统供需较为紧张的时段。此处所讨论的边缘成本，在理想条件下不仅包含系统内部的运维成本（如燃料成本），同时也包含对社会和环境所造成的外部成本，例如二氧化碳及废气排放给环境和健康带来的额外成本。自2017始，加州的政策规定覆盖全州的三大售电公司每三年就要上交相关数据并进行评估，以确保分时电价设计和系统边际成本相符。若评估表明现有分时电价和系统成本脱节，那么售电公司会提交新的分时电价标准，经政策制定者批准后，采用新的分时电价。
动态调整并不代表随意调整，对分时电价设计的调整应当建立在明确的目标和扎实的分析的基础之上。“明确的目标”具体是指通过推行分时电价希望达到的目的，例如降低系统电力成本，或者如《通知》中强调的，促进新能源消纳等。设计良好的分时电价往往可以同时达到多个目的，然而，没有任何一个分时电价设计可以一举达成所有的目标。在多个目标中分清主次，并围绕中心目标跟进总结，需要以扎实的分析为基础。目前中国的一大优势在于分时电价的大规模推行。各省不同的分时电价设计和电力供需情况，为政策研究提供了优质的异质性数据。通过对这些数据的详细分析，地方政府、省级电网公司、连同电力交易中心，可以量化环境和经济目标达成度，并总结过去经验，在此基础之上指导未来电价的设计。值得注意的是，近来已经有一些省份根据短期发电预期，及时调整了分时电价结构。例如广西在2021年出台了省内分时电价机制，并在2022年8月因来水偏好等原因，暂停实施了该年度夏季（7-9月）尖峰电价，且缩短了高峰电价时段。类似这样的动态调整对发电量预期做出了及时反馈，并调整分时电价以贴合系统实际成本。此外，河南省就在11月5日发布了新的通知，规定每年国网河南省电力公司都将向省发改委报告分时电价执行和电力系统运行的相关情况，并由省发改委进行评估和调整。若各省能将这种调整常态化、公开化，则更易于政策的平稳实施。
公开发布分时电价价格形成与峰段划分的方法论，及上述的常规评估、分析报告，有助于稳定社会投资、激发社会各界建言献策。这些方法的公开有利于需求侧资源投资者——例如分布式可再生能源、需求响应、储能——提前预判，按照未来政策走向布局投资。此外，公开资料也有助于研究机构、电力行业从业人士、以及电力用户积极提供建议，以便更有效地完善分时电价的设计。
在中国电力系统转型为以新能源为主体的新型电力系统的道路上，分时电价是一个不可或缺的里程碑。下一步，可以考虑在中央层面阐明建立分时电价动态调整机制的具体实施准则及时间线，在区域层面进行系统分析及常规评估，并在省级进行分时电价的最终微调。中国在分时电价的实施上已经走在世界前列：国际上，大部分分时电价的实施都还局限在地方层级，而仅有为数不多的国家像中国这样，在国家层面统一实施了分时电价。中国在分时电价上的坚持和成就为电力系统的绿色转型提供了坚实的基础，而分时电价电价设计的完善将进一步助力双碳目标的达成。
本文首刊于《中国电力报》(2022年12月6日)
在世界范围，分时电价机制正在逐渐普及。时至今日，大部分国家的分时电价都是根据使用时间，将发电相关成本分摊到不同的时间段中，同时在各个时间平均分摊电网相关成本。本文的主题是将分时电价机制的概念延展到配电系统定价中。
最近，一些国家和地区已经开始着手处理这一课题。在此，我们关注到了丹麦电力市场正在发生的变化，丹麦在将分时电价用于配电系统定价机制中已先行一步，有些经验可圈可点，我们在此梳理了一些相关经验，也许对世界各地的政策制定者有所启发。
本文修改版首发于《南方能源观察》
In a webinar for the Urban Sustainability Directors Network and the Southeast Sustainability Directors Network, David Farnsworth explored the power industry and how it is regulated in the public interest.
